Rotary-gear pump



y 2, 1929- J. SCHEMINGER, JR .719.025

ROTARY GEAR PUMP Filed April 17, 1924 Patented July 2, 1929.

UNITED STATES ATE T OFFICE.-

zronn .scnmmena, an, or PROVIDENCE, morn rsmma, essxenon, 3r imam-i nssremmn'rs, 'ro ra'rnonrmu nu AND rowan coxrnnz, or nawronx, n. Y.,

A CORPORATION 01 DELAWARE.

' Berna-arm rumr.

Application 'flled April 1'7,

This invention relates torotary gear pumps for pumping liquids and more'particularly to rotary gear oil pumps.

Excessive wear upon the gears with consequent noise and increasing chatter resulting from their continued use, has long been an objectionable feature in pumps of this character. Such wear is known to be caused largely by films of oil adhering to the gear teeth, and unavoidably trapped therebetween under great pressure as the pump gears are rapidly rotated in opposite directions.

The object of this invention is to provide a rotary gear pump casing in which the oil congestion or intense oil pressure upon and between the gear teeth will be wholly relieved, thus eliminating the excessive wear thereupon.

Simplicity in construction, efiiciency in operation, and incxpensc in cost of manufacture are further dcsidcrata contemplated in my improved rotary gear pump.

This invention will first be hereinafter more particularly described, with reference to the accompanying drawings, which are to be taken as a part of this specification, and then pointed out in the claim at the end of the description.

' In said drawings, Fig. 1 is asectional side elevation of my improved rotary gear pump, the gears being shown in elevation; I

Fig. 2 is an end sectional elevation of the same, taken on the line 22 of Fig. 1;

Fig. 3 is a plan elevation of the side plate of the casing taken on the line 33 of Fig. 2;

Fig. 4 is a fragmentary section taken on the line 4.-4: of Fig. 3; v

' Fig. 5 is afragmentary plan view of the side plate, illustrating a slight modification; and

.1 Fig. 6 is a fragmentary section taken on the line 6-6 of Fig. 5.

Referring to the drawings in which like reference numerals are used to designate corresponding parts throughout the several views, 7 denotes a rotary gear pump casing, the inner walls of which are shaped to conform facially and peripherally with inter meshing pump gears 8 and 9, which are mounted on shafts journaled in the sides of the casing, the latter being driven by its extended shaft 10 from any suitable source of power, and the former in turn being .rotat ably driven by the latter gear with which 1t 1m. Serial No. 707,580.

engages. It will benoted that the walls of the caslng closely embrace the cooperable intermeshmg gears in the usual manner in order that the pump may-maintain a maximum efficiency in pumping the oil without leakage around theperipheries or sides of the respect1ve ears. The pump casin (asshown) is secure le to the floor or a fixe part of the mechanism or apparatus with which it is associated and formed with threaded openlngs 1n 1ts top and bottom portions (above and below the plane of the gears) for connec tion with oil admission and pressure discharge pipes 11 and 12 respectively.

One wall of the casing is formed as a removable side plate 13 in order to permit access to the gears for any desired purpose.

In one or both of the side walls of the casng as shown in Figs. 1 to 4 on a vertical line intermediate the axes of the gear shafts and substantially below the horizontalplane thereof, is formed an elongated groove or recess 14 of Y-shaped form, which extends 1n the plane of the inlet and discharge ports and is of substantially the same depth its full length and has its open .side facing the intermeshing teeth of the gears with each branch of its forked end turned toward one of said shafts, so as to provide a vent or vents at the side or sides of t e intermeshing gears at the point where their" espective teeth are consecutlvely engaged with each other as the gears are rotated; said vent or vents extendin along said vertical line from near the point where the teeth engage to a point slightly above the axial centers of the gears and terminating short of the point where the teeth are disengaged, thus facilitating the displacement of any oil that may adhere to the gear teeth or be trapped therebetween and relieving the pressure of oil upon and between the engaging teeth and permitting it toescape from therebetween into the body or stream of oilbeing discharged from the pump casing under the impelling pressure of the revolving gears.

Referring to Figs. 5 and 6, in which a slight modification isshown, 15 denotes an oblong recess substantially angular when viewed in cross section and of substantially the same depth its full length, which may be formed in the side wall or walls of the casing -instead of the Y-shaped groove 14.- and arranged in the manner described with ref- .forked end with e erence to the Y-shaped form to adapt it to perform the same function as the latter'. However, the first described form is preferable and. advan us in providin a branch of the ork turned toward one of the gears in thedi-- rection of rotation thereof, so that any oil that may -be tra ped'between the gearteeth may esca at 1e deliveryend of the recess along 'eit er of two diverging linesor channels, thus more'efl'ectually relieving the ressure as the gears rotate in the direction indicated by the arrows in Fig. 1.

The simplicity, advantages and value of my improved gear pump casing in relieving the oil pressure upon and between the gear teeth and thus eliminating the excessive wear thereupon, will be obvious from the foregoing description, and it is therefore thought that further explanation is unnecessary.

I am aware that it has been proposed-to provide a rotary pump witha vent or by-pass in the side wall or walls of the housing, to permit the escape of water that may become pocketed between intermeshin teeth of the gears, and I do not broadly c aim any. such construction.

Having thus described my invention, what I claim as new and desire to secure by Lettellsk Patent of the United States is:

rotary gear .pump oompri a casing containing a pair of peripherall y i othed intermeshing gears" said casin havi'ngoppositel disposed inlet and disc arge ports exten ing in a lane'intersecting the intermeshin teeth and an elongated recess in its inner si e wall arranged at an intermediate point between the axes of said gears directly 0gp;

site 'said intermeshing teeth and exten along said plane from .near the oint where the teeth engage to a point slight y above the axial centers of the are and terminating short of the point w ere the teeth are disengaged; the delivery end of said recess being forked or bi-branched and each branch thereof extending in the direction of rotation of oneof the ears; said recess being of substantially unifbrm depth throughout its length, whereby a relief vent is provided directly opposite the intermeshing teeth and in close proximity thereto through which liquid may easily escape therefrom along converging lines.

In testimony whereof I aflix my signature.

- JOHN SCHEMINGER, R. 

